Southern Californian burger chain âIn-n-Out Burgerâ open a pop up restaurant in Swiss Cottage, London. Burger fans were queuing from 9 am for a chance to experience the cult burger. The restaurant is open from 11am till 3pm on September 21, 2016 in London, England.  The In-n-Out Burger chain from Southern California opened a pop-up shop for four hours in Swiss Cottage today and fans queued from 9am to experience the cult burgers.